Batteries are often used to power electronic devices, such as mobile phones, tablet computers, laptop computers, wearable electronic devices (e.g., watches, glasses), portable media players, portable gaming devices, robotic devices, and so forth. As electronic devices become smaller and lighter, batteries used to power the electronic devices are also reduced in size. For example, batteries have become thinner and have smaller surface areas to accommodate the reduction in size of the electronic devices that are being powered by the batteries. However, as the size of batteries decreases, the capacity to power electronic devices often decreases, as well. Decreases in battery capacity due to the reduction in the size of batteries can limit the functionality of electronic devices and/or degrade a user's experience.
One current thin battery package design includes stacked electrodes of alternating polarity. In order to provide external contacts to the current collectors of each electrode, i.e. conductive or metal layers of each electrode, portions of each electrode active areas are recessed to expose the underlying current collectors. The exposed portions are generally in alignment. However, since each electrode has a different polarity, the exposed portions of the current collectors for electrodes of one polarity are aligned with holes or vias within the current collectors of the electrodes having the opposite polarity. Since each electrode is separated by a separator layer, the separator layer also needs to be recessed in alignment with the exposed current collectors and holes to allow for a weld from the external contact to pass through the aligned current collectors, holes and recessed regions of the separator layer. This involves extra processing and costs in order to create the recessed regions within the separator layers.